Facebook is potentially insecure. As well as letting you be stalked by your ex-partners or parent, your activities and unguarded words can be visible to your current or future employer, and your personal details (like your full date of birth) can be harvested by identity thieves. Amazingly, the police have posed as Facebook friends to catch careless underage students who posted photos of themselves drinking.

Here’s an outdated but good conservative guide to privacy settings. Facebook recently changed its privacy settings, to much criticism, notably suggesting you make your personal information available to everyone on the internet, and making your list of friends public, even you’d made it private before (but there are instructions on how to make it private again).

Even if you’ve properly set up your own security settings, you are vulnerable to someone posting a photo of you doing something embarrassing (for example, wearing a leather tie printed with piano keys) and tagging you. You do have the option of de-tagging, and it’s not too hard to do.

It’s important to remember that all the information and media you post to Facebook is being hosted by a large, profit-making entity, who have repeatedly changed their privacy rules without warning. There is no guarantee that your personal information will not be sold, misused, or made public to the internet forever at some point in the future. If this worries you, set up your own website: one that you control.

More on managing Facebook privacy at ProfHacker here and here. Here’s a good recap of privacy settings to fix, and another one, that takes into account Facebook’s recent settings.

See also: The 12 most annoying types of Facebookers and fifteen things you should never do on Facebook.